P0328 Knock sensor 1 signal too high (bank 1)

P0328 knock sensor 1 circuit high input, bank 1 or single sensor

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A high knock sensor signal is usually an electrical fault, and the car normally keeps running. The source warns that real knock from heat or fuel problems needs prompt repair.

It gets more serious if:

  • Inspect soon: Inspect soon if the engine overheats, pings or knocks audibly, or loses power. These point to a real engine problem rather than a sensor wiring fault.

Source: how we rate severity

P0328 in short

P0328 means the bank 1 knock sensor is sending the computer a signal that is too high. A bad sensor, a damaged connector or harness, or a software issue is most likely. The car usually drives, but if it pings, runs hot or loses power, get it checked soon.

A knock sensor listens for the vibration of engine knock and sends a small voltage to the computer. The computer uses it to pull back spark timing. If that signal stays above the expected range, it sets P0328.

Most of the time this is an electrical problem: a faulty sensor, corroded or damaged wiring, or interference in the circuit. A low-fuel-pressure, poor-fuel, or overheating engine can really knock, so the source says to rule those out before replacing the sensor.

Some makers have bulletins: Kia has an ECM software update for 2010-2011 Soul 1.6L, Subaru has a knock sensor design change on 2.0L turbo models, and Audi has a bulletin for V6 TFSI knock sensor codes.

Most likely causes

  1. Faulty knock sensor

    Common general cause
    Why it ranks here
    The source lists the sensor first, and a high signal from the sensor itself is the simplest explanation.
    What would change this
    Rises if wiring tests good but the signal stays high. Falls if the circuit is damaged or the signal normalises when the connector is moved.
    How to test the knock sensor

  2. Damaged wiring, connector or interference in the sensor circuit

    Common general cause
    Why it ranks here
    The source lists damaged wiring or connectors and electrical interference among the main causes of a high signal.
    What would change this
    Rises if the harness is chafed or the connector corroded. Falls if a wiring check is clean.
    How to test the knock sensor

  3. Engine computer software or sensor design update (Kia Soul, Subaru turbo, Audi V6 TFSI)

    Supported by vehicle data
    Why it ranks here
    Kia TSBFUE024 (2010-2011 Soul 1.6L) is an ECM upgrade for P0328, Subaru 07-133-18 announces a knock sensor design change for 2.0L turbo models, and Audi TSB 2081342 covers V6 TFSI knock codes. Only the summaries were read.
    What would change this
    Rises on an affected vehicle with no wiring fault. Falls on other vehicles.
    How to test the engine control module (ecm / pcm)

  4. Real engine knock from heat, fuel pressure or octane

    Possible — needs testing
    Why it ranks here
    The source names low fuel pressure, wrong octane and overheating as causes, and warns against replacing the sensor when the real fault is cooling or EGR.
    What would change this
    Rises if the engine runs hot or pings. Falls if coolant temperature and fuel are normal.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Check coolant and oil level, engine temperature, and that the right fuel grade was used. Read all stored codes.

    Low risk

  2. Ask a dealer whether the vehicle has an open software or sensor update for knock sensor codes.

    Low risk

  3. Inspect the knock sensor connector and harness for corrosion, chafing or damage, and watch the sensor signal on a scan tool while tapping near the sensor.

    Use cautionTool: scan tool with live data, multimeter

    Warning:Work with the engine off and cool. Keep hands and tools clear of belts and moving parts.

Symptoms

  • Check engine light, often with no other change
  • Slightly reduced power or poorer fuel economy
  • Engine pings or knocks, or runs hot Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power

How to fix

  1. Check coolant and oil levels with the engine off and cool.

  2. Use the fuel grade the owner manual calls for.

  3. Ask a dealer about open updates for knock sensor codes on your vehicle.

Parts and cost context

  • Knock sensor:Check cooling and fuel first; replacing the sensor will not fix a real knock. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Kia

  • 2010–2011 · Soul

    Supported by vehicle data

    Kia TSBFUE024 is an ECM software upgrade for P0328 on the 1.6L Soul. Whether it is still current is not verified.

  • TSBFUE024Status unverified

    ECM upgrade for knock P0328 (Soul 1.6L)

    2010–2011soul · issued · NHTSA 10090741

    ECM software upgrade for some 2010-2011 Soul 1.6L with the MIL on and P0328.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Subaru

  • 2011–2017 · Forester

    Supported by vehicle data

    Subaru 07-133-18 covers a knock sensor design change on 2.0L turbo models, including P0328. Whether it is still current is not verified.

  • 07-133-18Status unverified

    Knock sensor design change, P0327/P0328/P0332/P0333

    2011–2017forester, wrx, crosstrek, legacy, outback, impreza, brz · issued · NHTSA 10140468

    2.0L turbo models only; the knock sensor design changed and a knock sensor code may set. The summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Audi

  • 2020–2026 · Q7

    Supported by vehicle data

    Audi TSB 2081342 covers knock sensor codes including P0328 on V6 TFSI models. Whether it is still current is not verified.

  • TSB_2081342_1Status unverified

    Drive system malfunction with knock sensor DTCs (V6 TFSI)

    2019–2026q7, a6 · issued · NHTSA 11031044

    Information for a drive system malfunction with P0327, P0332, P0328 and P0333 on V6 TFSI engines. The summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0325Knock sensor 1 circuit fault (bank 1 or single sensor)

    Same system Common general cause

    P0325 is the general knock sensor 1 circuit code and shares the sensor and wiring causes.

All Ignition and engine position sensors codes

P0328 questions

Should I replace the knock sensor right away?

Not first. Check the wiring and connector, coolant, fuel pressure and fuel grade, and ask about bulletins. Replace the sensor if those are fine and the signal stays high.

Is it safe to drive with P0328?

Usually, if the engine runs normally. Get it checked soon if it pings, overheats or loses power.

Sources and review

  1. Guide to P0328 OBD error code — PartsAvatar
  2. Kia bulletin TSBFUE024: ECM upgrade, knock improvement DTC P0328 (2010-2011 Soul 1.6L) — Kia (via NHTSA manufacturer communications flat file) ,
  3. Subaru bulletin 07-133-18: Knock sensor design change, P0327/P0328/P0332/P0333 — Subaru (via NHTSA manufacturer communications flat file) ,
  4. Audi bulletin TSB_2081342_1: Drive system malfunction with knock sensor DTCs P0327/P0332/P0328/P0333 (V6 TFSI) — Audi (via NHTSA manufacturer communications flat file) ,
  5. Cadillac bulletin 4721: Engine runs rough or MIL with P0326/P0327/P0328/P0336/P167D — Cadillac (via NHTSA manufacturer communications flat file) ,
Last reviewed
Written by
Saurabh K.
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